Thermostat.



A. S. GUBITT.

THERMOSTAT.

- APPLICATION FILED JUNE 16, 1910. 1,010,414. Patented Dec.5, 1911,

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llllllllllllllll|lIllll|l1ll|iIlllllllllllllllllllllllllllllIllIIWIINIIIIIINIW Witnesses Inventor fifjgj i- -fia ffrchibald s.'cu itt,

/8 His fittorney.

. UNITED STATES PATENT OFFICE.

ARCHIIBALD S. CUBITT, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL -ELECTBIC COMPANY, A CORPORATION OF NEW YORK.

THERMOSTAT.

mostats, of which the following is a specifi cation. v

This invention relates to thermostatic con trolling devices, and has for its object the provision of a device of this character which will operate to etl'ect certain desired results in a reliable and efficient manner upon a predetermined variation of temperature.

My invention relates more specifically to thermostatic switches for controlling electric circuits. In devices of this character, one of the great difliculties which has heretofore been encountered is in the provision of suitable means for causing the switch to operate quickly; that is, with a snap action. This is especially true where the thermostat has more than one operative position, and

the snap action is desirable in. all positions.

In carrying out my invention, therefore, I provide a thermostatic controlling device which will operate with a snap action and will be mechanically locked in operative position. I also provide means 'whereby the controlling device may have more than one operative position; the arrangements being such that the'controlling element willbe ppsitively locked in each position and will releasedfrom this position at a predetermined temperature with a snap action. I accomplish this result by having the thermostatic switch element-controlled by one or more thermostatic lockin elements. The thermostatic switch e ement gives the device the necessary bias or tendency to open, while the thermostatic locking element releases the switch element at a predetermined tem eratui'e. \Vhere the device is arranged wit two operative positions, I provide two thermostatic locking elements so arranged that when the switch element is released from one position it will snap to the op osite position and be locked by the other t ermostatic locking device. Upon another predetermined change of temperature, the switch element will be again released and return with a snap action to the first position as before.

In the accompanying drawing, in which I have shown my invention embodied in Specification of Letters Patent.

Patented Dec. 5, 191 1.

Application filed June 16, 1910. Serial No. 567,147.-

concrete form, Figure 1 represents a side view of my device, partly broken away; Fig. 2 r epr,esents a plan view of the same; Fig. 3 is -a'-- p'erspective View showing the circuitconnections; and Fig. ishows the arrangement of the thermostatic latches in de tail.

Referring to the drawing, 10 represents a thermostatic element having one end at fixed to a block of metal 11 mounted upon the base 12. This thermostatic element may be the compound type well known in the art, which bends in one direction when heated and in-the opposite direction when cooled. The free end of the element 10 is provided with a contact strip 13 arranged to move between the adjustable contacts 14 and 15. Securedto the block 11, on each side of the element 10 are two thermostatic strips 16 and 17. The planes 'of the two spectively. The end of the strip 16 is bent downward to form a lock or latch 18 beveled as shown so as to lock the contacts 13 and 14. in engagement, while the strip 17 has a similar latch 19 beveled in the opposite direction so as to lock the contacts 13 and 1.5 in engagement. Adjusting screws 20 and 21 are arranged, as shown, to vary the distance between the latches and the thermostatic element and thereby vary the temperature at which the element will be released. The two thermostatic strips 16 and 17 are arranged so that they move parallel with each other; that is, when latch 18 moves upward away from the element 10 the 11 and the other side of the line b is connected with the resistance R. The contact 14 is connected with an intermediate point of the resistance R, while the contact 15 is connected with the end of the resistance.

The operation of my device is as follows: Assuming that the device stands normally with the contact strip 13 between the two contacts 14 and 15, when the temperature rises the element 10 Willbe bent into the position shown in Fig. 2 and will be locked in this position by the latch- 19. This latch 19 has been moved upward to engage the element 10 by the rise in temperature, and the latch 18 has been likewise moved upward as shown in Fig. 1. When the thermostat cools oii the element will tend to bend in the OE. posite direction but will be restrained by t e latch 19. In the meantime the cooling off of the thermostat gradually lowers the latches l9 and 18, so that when a predetermined temperature is reached the element will be released and snap over into engagement with the contact 14. In this position it will be held by the latch 18 which has moved downward to engage it. By this arrangement the element is automatically locked in either position and always moves with a snap action. The temperature at which the device operated may be varied by means of the adjusting screws 20 and 21. It will thus be seen that I have provided asimple and reliable thermostatic switch which will be capable of fine adjustment and which will operate with a snap action in one or more positions.

-VVhile I have described my invention'as embodied in concrete form for purposes of illustration, it will be understood that I do .not limit my invention thereto, since various modifications will suggest themselves to those skilled in the art without de arting from the spirit thereof, the scope of which is set forth in the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States, is,- 1. A switch comprising a thermostatic switch element and a thermostatic locking element for engaging the same.

2. A switch comprising a thermostatic switch element and a thermostatic element for locking and releasing the same.

3. A switch comprisingamovable thermostatic switch element having two operative positions, and thermostatic means for controlling the movement thereof in each position.

4. A switch comprising a thermostatic switch element havin two operative ,tions, and thermostatic means for loc g the switch element in each position.

5'. A switch comprisingathermostatic element having two operative positions, and means for automatically releasing said element from either of said ositions and mechanically looking it in t e other position on predetermined variation in temperature.

6. A switch comprising a thermostatic element having two operative positions, and thermostatically controlled means for automatically releasing said element from either of said positions and looking it in the other position on predetermined variations in temperature.

7. A switch comprising amovable thermostatic switch element, and a thermostatic locking element movable in a plane perpendicular to the plane of movement of said switch element.

8. A switch comprisingamovable thermostatic switch element having two operative positions, and two thermostatic elements one for locking the switch element in each position, said elements being movable in a plane perpendicular to the plane of movement of the said switch element.

9. A switch comprising amovable thermostatic switch element having two operative positions, and two thermostatic locking elements one for locking the switch element in each position, said elements being each provided with a latch for engaging the switch element.

10. A switch comprising a movable thermostatic switch element, and a thermostatic locking element provided with a latch for engaging the switch element.

In witness whereof, -I have hereunto set my hand this 13th day of June, 1910.

AROHIBALD S. CUBITT.

Witnesses:

.T. P. THOMPSON,

F. G. LARAMEE. 

